Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Many dangerous gases are not easily detected by human senses. For instance, Radon-222 gas is odorless, tasteless, and invisible and thus cannot be detected by human senses. As radon-222 decays, it emits alpha particles, which can damage lung tissue and has been linked to causing lunch cancer in humans. Air quality monitors have been used to detect such dangerous gases. Often, however, the design of these air quality monitors may limit the number of gases that may be detected so that many different monitors may be required to detect a wide variety of gases. Additionally, traditional air quality monitors are large and in some cases the accuracy of the monitors may depend on outside factors, such as humidity, temperature, and gas concentration level.
The present disclosure recognizes that it may be difficult and/or expensive to sense liquids with a vapor pressure sufficient to reach a detectable concentration in air. It may be difficult and/or expensive to sense vapors released by a sublimating solid. It may also be difficult to detect a chemical vapor deposition monolayer thickness and/or corresponding gas phase concentration.